DOMXPath::registerPhpFunctions

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

DOMXPath::registerPhpFunctionsRegister PHP functions as XPath functions

Beschreibung

public DOMXPath::registerPhpFunctions(string|array|null $restrict = null): void

This method enables the ability to use PHP functions within XPath expressions.

Parameter-Liste

restrict

Use this parameter to only allow certain functions to be called from XPath.

This parameter can be either a string (a function name) or an array of function names.

Rückgabewerte

Es wird kein Wert zurückgegeben.

Beispiele

The following examples use book.xml which contains the following:

Beispiel #1 book.xml

<?xml version="1.0" encoding="UTF-8"?>
<books>
 <book>
  <title>PHP Basics</title>
  <author>Jim Smith</author>
  <author>Jane Smith</author>
 </book>
 <book>
  <title>PHP Secrets</title>
  <author>Jenny Smythe</author>
 </book>
 <book>
  <title>XML basics</title>
  <author>Joe Black</author>
 </book>
</books>

Beispiel #2 DOMXPath::registerPHPFunctions() with php:functionString

<?php
$doc
= new DOMDocument;
$doc->load('book.xml');

$xpath = new DOMXPath($doc);

// Register the php: namespace (required)
$xpath->registerNamespace("php", "http://php.net/xpath");

// Register PHP functions (no restrictions)
$xpath->registerPHPFunctions();

// Call substr function on the book title
$nodes = $xpath->query('//book[php:functionString("substr", title, 0, 3) = "PHP"]');

echo
"Found {$nodes->length} books starting with 'PHP':\n";
foreach (
$nodes as $node) {
$title = $node->getElementsByTagName("title")->item(0)->nodeValue;
$author = $node->getElementsByTagName("author")->item(0)->nodeValue;
echo
"$title by $author\n";
}

?>

Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

Found 2 books starting with 'PHP':
PHP Basics by Jim Smith
PHP Secrets by Jenny Smythe

Beispiel #3 DOMXPath::registerPHPFunctions() with php:function

<?php
$doc
= new DOMDocument;
$doc->load('book.xml');

$xpath = new DOMXPath($doc);

// Register the php: namespace (required)
$xpath->registerNamespace("php", "http://php.net/xpath");

// Register PHP functions (has_multiple only)
$xpath->registerPHPFunctions("has_multiple");

function
has_multiple($nodes) {
// Return true if more than one author
return count($nodes) > 1;
}
// Filter books with multiple authors
$books = $xpath->query('//book[php:function("has_multiple", author)]');

echo
"Books with multiple authors:\n";
foreach (
$books as $book) {
echo
$book->getElementsByTagName("title")->item(0)->nodeValue . "\n";
}

?>

Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

Books with multiple authors:
PHP Basics

Siehe auch

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